P0449 cel

[todds87ss]

All,
Got a p0449 code. Last couple of days. Now, when I reset it, it comes in immediately. IIRC, evap solenoid issue. Any advice?

[mi04se1]

DTC P0449: Evaporative Emission (EVAP) Vent Solenoid Control Circuit

Battery voltage is supplied to the EVAP canister vent solenoid valve. The ECM grounds the EVAP canister vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the EVAP canister vent solenoid valve as ON or OFF.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 5 seconds.

P0449
Ignition ON, engine OFF, command the EVAP vent solenoid Not Venting and Venting with a scan tool.
Listen for a click when the valve operates. Verify that both the ON and the OFF states are commanded.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Sounds like you have a bad evap solenoid.

[todds87ss]

the commanded opening of the purge valve starts at 26% or so, until the car is warmed and at speed, then goes to 100%. If I let off of the gas, it does drive the commanded % back to 26%. Then as I depress the accelerator again, and it immediately goes back to 100%. By you explaination, when the demand goes to 100%, the ecm is not seeing 100% after 5secs (valve not going full open). Does that sound right? I will check valve operation, but will find another way, as my scantool will not command.
Thanks fo the info.

[todds87ss]

I was confused. I swapped Purge solenoids with the GTO, and the code still appears. This is a vent sol issue, not a purge sol issue. Does anyone know where it is (vent solenoid), and how to get to it?
Thanks.

[mi04se1]

Remove the fuel tank assembly. Refer to Fuel Tank Replacement.



Support the evaporative (EVAP) emission canister assembly (1).
Remove the EVAP emission canister assembly to chassis retaining bolts (2).
Remove the EVAP emission canister assembly (1) from the vehicle.
Installation Procedure

[todds87ss]

So the only way to get to the solenoid is by removing the fuel tank??? Holy crap. Guess I'll try a new gas cap first...

[mi04se1]

Or if you still have a warranty, goto the dealer.

[todds87ss]

Or if you still have a warranty, goto the dealer.

not an option...

I just looked at en exploded view of the tank/canister, and cannot find a vent solenoid, nor an electrical connector at the canister. Am I missing something?

[todds87ss]

The warranty expired at 50K. The gas cap was a no fix. Still looking for the elusive evap vent solenoid. Anyone gotta a pic?

[mi04se1]

Part of canister (#4).